Values stored at different offsets

[Totte_ch]

Hey

A several times when I tried to hack a application, I have met values that appears at different offsets. I scan the program for a value and then I have got the offset. When I restart the program and view at the same offset, there isn't the same value there - it's gone!

How do you do when you want to change that value? - I mean, the value will change place at random...
Is there a "real" offset somewhere else? How do you find it?


Thanks for help
Totte_ch

[Mr.Lampy]

its called DMA there is a tut on here for it
Beginner's Guide to DMA

[Dyndrilliac]

That page does not exist.

Correct link for Fish Beans' DMA Hacking Tutorial: Beginner's Guide to DMA

Unfortunately, Fish Beans' guide is not all-inclusive. There are other things that you can do to get around DMA besides simply alter the instructions the game/program uses to modify values that have been allocated memory on the fly. For example, it would not be difficult to write a hook that gives you the pointers to the values that the game uses to change them - but it would require the constant presence of your own code running in the address space to receive said pointers. After all, simply knowing the pointers isn't enough since they will simply change the next time the game is run. Your hack will need to be able to retrieve them and use them consistently.

DMA from a developer/programmer's standpoint: Dynamic memory allocation - Wikipedia, the free encyclopedia

It is equally important to understand DMA from the point of view of the programmer as it is to simply knowing how to go about circumventing it.